I. Field of the Invention
This invention relates to membranes adapted for the waterproofing and sealing of substrate structures, particularly in roofing applications, and to the method of manufacturing such membranes. More particularly, this invention relates to waterproofing membrane laminates having a leading edge portion which constitutes a starter strip for receiving thereon the first row of roofing shingles, and a non-slip trailing edge portion which constitutes an underlayment for receiving thereon successive rows of roofing shingles.
II. Description of the Prior Art
Bituminous prepared roofing, also referred to as asphalt roofing membrane, is typically manufactured using as a base a fibrous web, and coating or impregnating one or both surfaces of the web with a weather-resistant bituminous coating material. Usually, there is applied to the bituminous coating, on the surface intended to be exposed to the weather, a suitable granular, material such as slate granules or mineral surfacing. A release sheet, such as siliconized paper, is applied against the self-adhesive bituminous waterproofing layer to prevent sticking of adjacent sections of the roofing material in the package.
In a typical installation, an underlayment is first applied to the plywood deck of the roof. The underlayment may take the form of a fibrous mat also impregnated with a bituminous material, and useful as a waterproofing member. The roofing shingles are applied on top of the underlayment with the seams of adjacent rows in off-set relation. In practice, a starter row or strip is begun at the roof eaves using self-sealing shingles. The end of the first shingle in the strip is trimmed such that in the placement thereof on the deck, the cutouts of the first course of shingles will not be placed over the starter strip joints. The starter strip also is nailed to the eaves. Successive rows of shingles are then secured to the deck or roof in conventional manner using sealants or nails.
To insure maximum protection against ice dams, flashing should be installed wherever there is a possibility of icing, such as along the eaves of the roof. Ice dams are formed by the continual thawing and freezing of melting snow, or the backing up of frozen slush in gutters which force water under the roofing thereby causing damage to a home's ceilings, walls, and insulation. This problem is most acute on low slope roofs; that is, roofs with a slope of 2 inches (5.08 cm) to 4 inches (10.16 cm) per foot (30.48 cm). Eaves flashing is the recommended method of applying roofing material to this potentially vulnerable area to help prevent such leakage. The flashing is positioned over the underlayment and nailed in place ready to receive thereon the starter strip.
The traditional eaves flashing have been either 50 pound coated felt or two layers of 15 pound saturated felt cemented together. The term "pound" is defined as the weight of the felt in covering an area of 108 square feet. The asphalt used in the 50 pound felt is not modified with rubber, and after aging, will not form a good seal around nails. The installation of two layers of 15 pound saturated felt is time consuming.
As is apparent, the need for a starter strip and for flashing involves two separate elements which are installed separately, thus increasing installation time. Also, the use of an ice dam barrier, such as flashing, tends to be slippery when standing upon. This creates a safety hazard for the installer.
The present invention combines the separate functions of a starter strip and eaves flashing into a single roofing membrane, and incorporates a nonslip safety feature as part of the membrane in the manner hereinafter described.